In our last update we invited you to come to the YAC to look at a broccoli trial we have in which we sprayed Trifluralin at 1.5 pt/ acre preemergence (PREE) incorporated mechanically. The application was made to the flat ground then incorporated with a disk at 4”depth. Then rows were built, and broccoli was direct seeded and germinated with sprinkler irrigation. Last year we saw injury in a non-disked Treflan treatment, so I didn’t include it in the trial. The same procedure was done with Prowl at 1pt with disked and non-disked plots.

Additional PREE treatments were Devrinol at 1pt/a, Prefar6qt/a, Goal tender at high rate of 16floz/a.

Prowl mechanically incorporated looks better than Non-incorporated in weed control as well as not showing phytotoxicity symptoms. Treflan, also mechanically incorporated looks similar to Prowl with a very small number of large weeds. The predominant weeds in this field are goosefoot and lambs quarter and are showing restricted growth not being as competitive with the broccoli.  

Our observations in the trial as well as your field experience shows us with Treflan and Prowl available PREE and the post emergence herbicides such as Clethodim and Goal the absence of Cacthal can be mitigated to some degree. Again, you are welcome to come look at it at the Yuma Ag Center.

Treatments didn’t affect broccoli stand except Goal high rate PREE as expected.

Prowl and Treflan applied on the flat and incorporated mechanically did not produced phytotoxicity symptoms at 13 and 28 days after planting.

All weeds were about 0.5” at the time of this evaluation.

Some of the small weeds observed in the 13-day evaluation in the disked Prowl and Treflan died or didn’t grow by day 28.